JPH0581018U - Vulcanized fiber sheet with saw blade and carton to which the sheet is adhered - Google Patents

Abstract

(57) [Abstract] [Purpose] A sheet with a saw blade for cutting the film, which is used by attaching it to a carton case in which a cooking sheet such as a synthetic resin film is wound in a roll and stored. Especially, this saw tooth blade is made of vulcanized fiber, and it is an object to improve the hygroscopicity which is a defect by utilizing rigidity and elasticity which are advantages of the vulcanized fiber. [Structure] Therefore, a moisture-proof coating made of a synthetic resin is formed on both sides of the vulcanized fiber raw material, and the saw tooth blade sheet having the coating formed thereon is adhered to a carton using the coating.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention is a sheet with a saw blade for cutting a so-called cooking sheet such as a synthetic resin wrapping film, paper or a metal foil, and a carton casing to which the sheet with a saw blade is adhered. Pertains to

[0002]

[Prior art and its problems]

 Materials commonly called cooking sheets, such as synthetic resin wrapping films and aluminum foils used for packaging foods in kitchens, etc., are usually rolled into rolls and then made from paperboard. It is stored in a carton case (hereinafter referred to simply as a carton). In use, after the end of the film or aluminum foil is pulled out from the carton, the cutting blade attached to the front part or lid of the carton, that is, the cutting blade formed in a sawtooth shape. It is cut to a desired length for use by cutting it through (hereinafter, simply referred to as a cutting blade or a sawtooth blade).

Incidentally, the cutting blade attached to the carton is generally made of metal in general, but recently, a cutting blade made of vulcanized fiber has been put on the market. If it is a metal cutting edge, it is easy to damage the fingers when grasping the carton, but if it is made of vulcanized fiber, there is no such anxiety, on the other hand, when the film or foil is finished, the carton This is because it can be incinerated.

The cutting edge made of vulcanized fiber has the above-mentioned advantages, but on the other hand, it has the drawback that it absorbs moisture to cause elongation when it is left in a humid atmosphere for a long period of time due to the properties peculiar to the material. have. Therefore, conventionally, a melamine resin solution, a glyoxal solution, a polyurethane resin solution, or the like is applied to the surface of the raw material of the vulcanized fiber to impart moisture resistance, and then a cutting edge is formed for practical use. However, satisfactory results are not always obtained, and further improvement is desired. In other words, when a vulcanized fiber cutting blade is placed in a kitchen, where the humidity is particularly high, it may expand due to the humidity in the atmosphere, and it may be water-resistant and waterproof. However, in an extreme case, due to elongation due to moisture absorption, the cutting edge and the carton to which the cutting edge is adhered are locally separated and the function of the cutting edge is deteriorated. May occur.

[0005]

[Means for solving problems]

 In this case, the present invention is designed to minimize the influence of moisture in the atmosphere, and as a cutting blade for cutting the sheet fed out from the carton, it is capable of exhibiting a sufficient cutting function from beginning to end. -The purpose is to obtain In other words, a vulcanized fiber saw blade sheet with extremely high dimensional stability against moisture is obtained.

The present invention is a moisture-proof film having a low moisture permeability, which is selected from a polyolefin resin film, a polyester resin film or a polyvinylidene chloride resin film on both sides of a vulcanized fiber constituting a saw blade sheet. It is intended to solve the above-mentioned problems by forming a. In addition, a polyethylene film, a PET film, etc. are mentioned as a typical example of the above-mentioned resin film.

The moisture-proof film may be formed directly on the surface of the vulcanized fiber, but prior to that, it may be formed by applying a melamine resin, glyoxal, or other water-proofing agent. It is needless to say that the moisture-proof film may be formed after water-proof or waterproof treatment. Incidentally, in order to improve the adhesion between the moisture-proof coating and the vulcanized fiber, the following means can be adopted. That is, prior to coating the vulcanized fiber surface with an anchor coating agent such as polyethyleneimine, or before laminating the moisture-proof coating to the vulcanized fiber surface, the corona is preliminarily applied to the surface of the resin film to be the moisture-proof coating. There are methods such as performing discharge processing.

The shape of the entire cutting edge in the sheet with a saw blade may be straight as described above, or the entire shape of the cutting edge may be bent in the longitudinal direction to form a mountain shape. May be.

Furthermore, the invention includes an invention in which the end surface of the saw blade after forming the saw blade as described above, more specifically, the concave portion of each cutting blade, is also subjected to water resistance treatment. In this case, the following processing is performed on the periphery of the blade after the formation of the sawtooth blade. That is, one of them is a method in which the edge surface of the blade is also subjected to water resistance treatment by applying or impregnating an organic solvent solution of each resin having relatively high fluidity or various water resistance agents other than the above. In addition to the above, a waterproof film is formed by applying an ionizing radiation curable resin such as an electron beam curable resin (EB resin) or an ultraviolet ray curable resin (UV resin) to the end face of the blade and then curing the resin. May be formed. Since the waterproof film after curing with the ionizing radiation curable resin has extremely high hardness, it has the effect of preventing water from penetrating from the end surface of the saw blade and improving the strength of the blade itself. By the way, the above-mentioned waterproof treatment is a concept including so-called waterproof treatment for preventing infiltration of moisture.

[0010] Incidentally, after forming the moisture-proof coating on both the front and back surfaces of the vulcanized fiber, the waterproof coating may be formed on the end surface of the saw blade in the second step. Alternatively, a raw material of vulcanized fiber may be previously impregnated with a waterproofing agent, and a moisture-proof coating may be formed on both surfaces thereof before forming the saw blade.

As described above, in the present invention, a vulcanized fiber piece formed by forming a saw blade, that is, a sheet with a saw blade is attached to the carton described above. Can use an appropriate pressure-sensitive adhesive or adhesive (including a pressure-sensitive adhesive). However, when the following bonding method is adopted, the pressure-sensitive adhesive described below is used more than when the pressure-sensitive adhesive or the adhesive is used. As described above, excellent effects can be obtained in various aspects.

The bonding method means that the saw blade cutting sheet is superposed on the paper board constituting the carton and then formed on the surface of the sheet by ultrasonic welding. This is a method in which the paperboard and the sheet with a serrated blade are welded to each other through a moisture-proof coating, and the thus-bonded sheet is peeled off even if it is exposed to a high-humidity atmosphere. It was confirmed that this did not occur.

Thus, the present invention makes it possible to maintain a vulcanized fiber saw toothed sheet in a state in which it is unlikely to be affected by humidity. Therefore, even though the vulcanized fiber is used as a material, the saw tooth is extremely rich in dimensional stability. Since it is a sheet with a blade, it has a high cutting performance of the saw blade, and even when this sheet is bonded to the carton, there is no risk of peeling at the bonding site and it is strong. It is possible to provide a carton with incisors bonded to the.

The main material used in the present invention is vulcanized fiber, and as is well known, it uses cotton fiber or chemical pulp as a raw material, and a raw paper produced without size is made to have a predetermined concentration (generally, a bokeh degree of 65 to 65). It is treated with the zinc chloride solution of 74), has the properties intermediate between wood and metal, has high elasticity and rigidity, is far lighter than metal, and is highly resistant to various oils. Have resistance.

The present invention utilizes the above-mentioned properties of the vulcanized fiber, and by subjecting this to the special processing as described below, the above-mentioned sheet with a saw-tooth blade is obtained. It is possible to provide a carton with a cutting edge, which is highly useful as an alternative to the conventional metal blade by being adhered to the. The thickness of the saw tooth blade sheet is about 0.2 mm to 0.5 mm, preferably about 0.25 mm to 0.35 mm, and the thinner the sheet, the better the sharpness.

In the present invention, the above-mentioned raw material of the vulcanized fiber may be used as it is as a raw material for a sheet with a saw blade, but this vulcanized fiber is previously mixed with a melamine resin solution or a glyoxizer. It may be used after being coated or impregnated with a solvent solution to impart water resistance.

The method for forming the moisture-proof film provided on the surface of the raw fabric will be described in detail. An emulsion or a solution of various resins having low moisture permeability selected from the above-mentioned polyolefin resin, polyester resin, polyvinylidene chloride resin, etc. In the form of coating on the surface of the raw fabric, or dry laminating in the form of a film, and further, holding each of the resins in a molten state and extruding the resin on the surface of the raw fabric. It is possible to adopt a method such as

Among them, a method of laminating a polyolefin resin having a low moisture permeability such as polyethylene, polypropylene or methylpentene polymer on the surface of the vulcanized fiber by melt extrusion is preferable.

When a sheet with a saw blade having the above structure is attached to a carton blank, a polyethylene resin or the like is used as an adhesion promoter on the carton side at a portion corresponding to the adhering portion. If the emulsion is applied in advance to form a film, the adhesive strength between the two is further increased.

Hereinafter, the present invention will be described more specifically based on Examples and Comparative Examples. Example 1 First, a method for producing an original fabric of vulcanized fiber used for producing the vulcanized fiber saw toothed sheet will be briefly described. As a pulp to be used, a stock containing 50% each of NBKP and NDSP is used to make a base paper having a basis weight of 105 g / m ² . Two sheets of this base paper were soaked in a zinc chloride solution at 69 ° Baume and 40 ° C., then squeezed, heated and pressure-bonded, and aged in a zinc chloride solution tank at about 30 ° Baume. Aging is performed in a solution tank to elute zinc chloride. Then, after pickling in a hydrochloric acid tank, it is sent to a water washing tank to remove zinc chloride. After that, preliminary drying is performed, and then both surfaces are coated with a melamine formalin resin solution (10 g / m ^{2 in} terms of solid content), and then dried with a cylinder dryer. Then, calendering was further performed to obtain a 0.25 mm thick vulcanized fiber raw material rich in water resistance.

[0021] After applying an anchor treatment by coating polyethyleneimine at a solid content of 3 g / m ² on both front and back sides of this raw material and drying, the low-density polyethylene melted on the treated surface. Extrusion coating was performed to form a moisture-proof coating composed of a low-density polyethylene layer having a thickness of 20 μm on both sides.

Thus, as shown in FIGS. 2 to 4, a vulcanized fiber plate 3 having a moisture-proof coating 2 made of the polyethylene layer formed on both front and back surfaces of a strip-shaped vulcanized fiber web 1 can be obtained. The sheet 4 with saw blades made of vulcanized fiber as shown in the figure can be easily obtained by mounting on a saw blade forming machine or punching with a press or the like.

By the way, the original fabric has a directionality due to the orientation of the constituent fibers during papermaking. That is, since the constituent fibers tend to be arranged parallel to each other along the papermaking direction, the longitudinal direction of the original fabric, that is, the machine direction (MD direction) and the direction orthogonal to the longitudinal direction of the original fabric, which is made accordingly The physical properties of the original fabric differ from (CD direction). Considering the expansion / contraction ratio particularly when moisture is absorbed, the expansion / contraction ratio of the above-mentioned material in the CD direction in FIGS. 3 to 4 is 6 to 7 times higher than that in the MD direction. Specifically, taking elongation as an example, the elongation when the relative humidity is changed from 65% RH to 90% RH (atmosphere temperature of 23 ° C. for 24 hours) is 0.4% in the MD direction. The CD direction shows a value of 2.7%.

Therefore, when a sheet with a saw blade was prepared from the above-mentioned original fabric, the saw blade was formed in a state as shown in FIG. 3, and this sheet was used by being attached to a carton. Occasionally, due to the above-mentioned elongation, the sheet with saw blades bends in a wavy manner on the carton, causing local peeling. As a result, the sharpness of the saw blade itself is impaired, resulting in a problem that the sharpness is extremely reduced. By the way, in the state as shown in Fig. 4, that is, when the saw blade is formed along the MD direction, the expansion and contraction rate is small, so the above phenomenon does not occur. Since there is a value that matches with, there is virtually no problem.

The present invention is intended to solve the problem in the CD direction, and in order to achieve the purpose, a moisture-proof coating is formed on both sides of the original fabric. According to the invention, when forming a sawtooth blade on the original fabric 3 processed as described above, the sawtooth blade may be formed in any of the MD direction and the CD direction (see reference numeral 4a or 4b in the figure). ) Can be formed.

According to the present invention, after the moisture-proof coating 2 is formed on both sides of the original fabric 1 under the above-mentioned intention, a sheet with a saw blade having a shape as shown in FIG. 1, that is, a saw tooth having an elongated rectangular shape as a whole. The bladed sheet 4 was obtained, and as an example, a 0.8 cm × 30 cm flat plate-shaped sheet with a saw blade having a thickness of about 0.25 mm was obtained.

Example 2 In order to waterproof the end face of the saw blade 4a in the saw tooth blade-containing sheet 4 obtained in Example 1, the epoxy blade of the epoxy acrylate type having a viscosity of 400 cp was provided around the saw blade, as an example. After the curable resin liquid was applied through an appropriate gravure roll, the ultraviolet ray was irradiated to form an ultraviolet curable resin film on the end face of the sawtooth portion.

Example 3 The same process as in Example 1 was carried out except that a vulcanized fiber raw fabric having a rice basis weight of 400 g / m ² was used to form a moisture-proof coating made of a polyethylene film on both sides of the raw fabric. Then, the cutting blade was punched and formed into a sheet with a saw blade. In this case, the thickness of the sheet with the saw blade was 0.35 mm, and the saw blade was formed on each of the two long sides of the rectangular sheet. Further, the end face of the saw blade was also subjected to water resistance treatment in the same manner as above.

On one side of the moisture-proof coating 2 in the saw-toothed sheet 4 of the above-mentioned form, corona discharge treatment is carried out to activate the coating surface, and after being made an easily adhesive surface having a surface tension of 40 dyne / cm, The sheet was adhered to a predetermined position of the developed carton blank shown in FIG. 5 through a pressure-sensitive adhesive.

The configuration of the carton will be described below with reference to FIGS. In the figure, reference numeral P is a carton blank (0.8 mm thick) made of paperboard having a basis weight of 350 g / m ² , and reference numeral 11 is a rectangular bottom plate formed by partitioning the blank through fold lines. In the figure, the front plate 12 is continuously provided on the long side located below the bottom plate, and the other long side is connected to the back plate 13, the top plate 14 and the cover plate through the same folding line as described above. 15 are provided so as to be adjacent to each other. Adhesive pieces 16 and 17 are extended on both sides of the front plate 12 and the rear plate 13 through folding lines, and a flap 18 is also attached to the short side of the bottom plate 11 in the same manner. Extend the gable board 19, respectively.

The lid plate 15 is provided with a C-shaped breaking line 20 and a linear breaking line 21 continuous with the breaking line 20 as shown in FIG. Make sure to use a tear line to open the package. After assembling, a part of the lid plate 15, that is, the part of the temporary attachment piece 23 surrounded by the break line is cut off from the carton main body, and at the same time, it is opened between the break lines 20 of the V-shape. After opening the formed insertion piece 22, the insertion piece 22 is inserted into the locking slit 24 formed in the front plate 12 to fix the lid.

The above-mentioned sheet 4 with saw blades is to be adhered to the boundary between the bottom plate 11 and the front plate 12 at the bottom side of the bottom plate 11. At the time of bonding, the saw blade 4a of the sheet is cut from the fold line of the boundary. Adhesive and fixed to a position where it slightly protrudes. When the sheet with the saw blade is attached to the carton, it is preferable that the sheet is attached so that it is slightly shorter than the long side of the bottom plate 11 in the longitudinal direction.

When assembling the developed carton blank, as shown in FIG. 6, the front plate 12, the rear plate 13, and the end plate 19 are vertically centered around the bottom plate 11 via fold lines. After being started up, the adhesive pieces 16 and 17 are positioned inside the end plate 19 and adhered, and then wound into a roll shape with the above-described cooking sheet (see reference numeral G in FIG. 7). To house. Then, after covering the opening surface with the top plate 14 and the lid plate 15, the lid plate is closed by spot-bonding H to the front plate 12 through the temporary attachment pieces 23 and the like.

When the cooking sheet F stored in the carton as described above is taken out, as shown in FIG. It is cut and opened, and then the edge of the lapping film or sheet F wound as the roll G is picked to draw out a desired length. The drawn film or the like is hung down from the upper edge of the front plate 12 along the plate 12, and further pressed in the direction of the front plate 12, so that the saw blade 4a protruding to the lower edge of the front plate 12 is formed. Cut it to the required length. After the cutting, the insertion piece 22 is inserted into the locking slit 24 formed on the front plate 12 and the opening is closed to prevent dust from entering the carton. It is a thing.

Example 4 Next, an example in which the form of the above-mentioned sheet with saw blades, strictly speaking, the sheet with saw blades presenting a mountain shape in which the distribution state of the saw blades does not appear linear explain . As shown by reference numeral 5 in FIG. 8, when the array of saw blades is seen in a plan view, it is composed of a flat plate member in a distributed state in which the central portion in the lengthwise direction is projected and slightly inclined toward the ends. This is a sheet 5 with a saw blade, and this is an example in which this sheet is bonded to a carton blank P'having a developed shape similar to that in the above-mentioned embodiment.

That is, at the position shown on the cover plate surface of the carton blank, a pressure-sensitive adhesive similar to the one described above or a hot-melt type adhesive, or any other adhesive means is used to form a blade with a saw blade. -Gat 5 is adhered.

The configuration of this carton blank will be briefly described below. A lid plate 25 is continuously provided on the upper side of the top plate 14 of the blank, but the lid plate has a different form from that of the above embodiment. The sheet 5 with a saw blade is adhered, and a breaking line 26 having a shape conforming to the shape is formed on the lid plate. When the roll-shaped film or sheet stored in the carton is taken out, the separating piece 27 located on the outer side is removed through the breaking line 26 along the breaking line. And then open the carton. When the separating piece 27 is separated from the lid plate 25, the portion of the saw blade 4a in the saw blade-equipped sheet 5 is exposed from the edge of the lid plate. It is possible to cut the film or sheet into a desired length. By the way, among the reference numerals shown in the carton blank P ′, the same reference numerals are given to the members common to the embodiment (see FIG. 5).

A material for facilitating pre-adhesion, such as a modified polyethylene emulsion, is pre-patterned using a gravure coater or the like at the adhering point on the carton blank side to which the sheet with a saw blade is adhered. If the blank is supplied to the die set mechanism after being processed, the bonding strength by the ultrasonic bonding can be further increased, and the bonding speed can be improved.

As described in detail above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the invention.

Next, in order to confirm the effect of the moisture-proof coating of the present invention, the following test was conducted using the following samples. That is, sample A: a raw sheet prepared according to Example 3 above (a melamine resin solution (5% concentration) in advance with respect to a vulcanized fiber plate (thickness 0.35 mm) having a rice basis weight of 400 g / m ² ). After being impregnated with the same, a low-density polyethylene film with a thickness of 20μ was formed on both sides of the dried raw material. Sample B: For a vulcanized fiber plate (same thickness) with the same rice basis weight as above (Impregnated with a melamine resin solution (5% concentration)) Sample C: A vulcanized fiber plate (with the same thickness) having the same rice basis weight as the above was previously impregnated with a 5% concentration melamine resin solution. The above resin solution was further applied at a rate of 15 g / m ² (solid content))

A rectangular plate having a width of 8 mm and a length of 100 mm was cut out from each of the samples, and the saw blade was formed as shown in FIGS. Orientation is set to the length direction, and the length direction is parallel to the MD direction (indicated as "longitudinal" in Tables 1 and 2 below), and the CD direction matches the length direction of the saw blade. The following two types were prepared (see "Horizontal" in Tables 1 and 2 below), and the degree of expansion and contraction of each sample due to the difference in humidity was tested.

As a test method, each sample was left in an atmosphere of 23 ° C. and 65% RH for 24 hours, and the elongation in the length direction of each sample was measured to obtain a reference value. .. Then, this time, each sample to be measured was placed in an atmosphere of 20% RH and 90% RH and left to stand for a predetermined time (each time shown in the table below), that is, when the conditions were changed. Tables 1 and 2 below show the percentage of elongation or shrinkage of the above measured value as a percentage.

[0043]

[Table 1]

[0044]

[Table 2]

As is clear from Tables 1 and 2, according to the present invention, the vulcanized fiber plate, which is relatively susceptible to the humidity in the atmosphere, is also affected by the humidity due to the moisture-proof coating formed on the surface thereof. It was confirmed that it could be kept in a difficult state. In particular, the moisture-proof treatment by forming the moisture-proof film of the present invention has remarkable effects as compared with the conventional products, as compared with the water-resistant products made of the above-mentioned melamine resin or urethane resin which are generally used. In addition, it is particularly preferable to use a polyolefin resin film having a relatively low moisture permeability as the moisture-proof film.

Furthermore, according to the present invention, by using the moisture-proof coating, even in the case where water-resistant or waterproof treatment with melamine resin or urethane resin, which has been indispensable in the past, is required, a light treatment is sufficient. There is no need to use expensive urethane resin, and as a result, it is extremely advantageous in that it can provide highly practical products at low cost. In other words, comparing with the one coated with urethane resin such as vulcanized fiber laminated with polyethylene, the former does not need to be 1/5 of the latter in terms of the unit cost of resin used, and the former is also the latter in terms of processing speed. Since it is 30 times more efficient, the product according to the invention can provide it at very low cost.

Thus, the present invention uses the vulcanized fiber plate having the moisture-proof coating formed thereon as a raw material, and makes use of the very high elasticity and rigidity of the fiber itself to form a saw blade on this material. Since it is made to work, there is no deformation or crushing of the saw blade due to external force, and it always exhibits sharp cutting performance. In particular, the sheet according to the present invention does not impair the dimensional stability even in a kitchen or kitchen where the humidity in the atmosphere is high. It is suitable as a cutting blade for cutting a cooking sheet such as metal foil or processed paper.

In addition, since the saw tooth blade-made sheet is made of vulcanized fiber, the sheet does not damage the fingertips during handling even when attached to the carton and used. As a whole, the used product can be incinerated as it is, and there is no residue like the conventional metal blade.

Furthermore, in the case where the saw tooth blade sheet of the present invention is attached to the carton, there is almost no difference in expansion and contraction even when it is exposed to moisture in the atmosphere, and it constitutes a carton. Since there is no relative expansion / contraction difference with the paperboard, the serrated sheet after being attached to the carton does not peel off or deform due to the effect of humidity, and thus is always stable. It has the advantage of exhibiting the cutting function.

As described above, the present invention is a saw-tooth blade sheet for cutting a cooking sheet used for food packaging in a kitchen or the like, and a carton cage made of paperboard provided with the sheet. -Since the sheet is made of vulcanized fiber and can be used as a substitute for a metal blade that is widely used nowadays, the carton case that consumes a lot of -When the waste has been used, it is possible to incinerate the entire carton case including the saw blade blade, and it is possible to recover it as waste paper pulp. It is also highly useful in terms of preventing environmental pollution.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a vulcanized fiber-made saw toothed sheet according to the present invention.

FIG. 2 is an enlarged sectional view taken along line II-II in FIG.

[Fig. 3] After forming the moisture-proof coating on both sides of the vulcanized fiber material, a saw blade is formed in a direction perpendicular to the paper-making direction of the material (CD direction = Cross Direction). It is a top view showing the case where it is set to -G.

FIG. 4 is a view for obtaining a sheet with a saw-tooth blade from the original fabric,
It is a top view which shows the case where a sawtooth blade is formed in parallel with the papermaking direction (MD direction = Machine Direction) of this original fabric.

FIG. 5 is a development view showing an embodiment of a carton blank provided with the above-mentioned sheet with a saw blade.

FIG. 6 is a perspective view showing a state in which the carton blank shown in FIG. 5 is assembled and is opened.

FIG. 7 is a perspective view showing a state in which, after the carton is opened, the roll-shaped cooking sheet housed in the carton is pulled out and cut.

FIG. 8 is a development view showing another embodiment of a carton blank to which the above-mentioned vulcanized fiber-made sheet with a saw blade is adhered.

[Explanation of symbols]

 1 Raw Fabric 2 Moisture-Proof Film 3, 4 Sawtooth Blade Sheet 4a Sawtooth Blade 11 Bottom Plate 12 Front Plate 13 Back Plate 14 Top Plate 15 Cover Plate 16, 17 Adhesive Piece 19 Gable Plate 20 Break Line 22 Insert Piece 23 Temporary Piece 24 24 Stop slit 26 Break line

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroaki Mikamo 300 Hiragaki, Fuji City, Shizuoka Prefecture Honshu Paper Manufacturing Co., Ltd.

Claims (5)

[Scope of utility model registration request] 1. A sheet with a saw blade made of vulcanized fiber in which at least one edge of a sheet obtained by forming a moisture-proof coating on both sides of a raw sheet made of vulcanized fiber has a saw blade shape. 2. The vulcanized fiber saw blade sheet according to claim 1, wherein the moisture-proof film is a resin film having a low moisture permeability selected from any one of a polyolefin resin film, a polyester resin film and a polyvinylidene chloride resin film. 3. A vulcanized fiber saw blade according to claim 1 or 2, wherein the surface of the vulcanized fiber raw fabric is coated with melamine resin, glyoxal or other water-proofing agent and then the moisture-proof coating is formed. Attached sheet. 4. A bottom part of a carton having a carton body composed of a bottom plate, a front plate, a back plate and a gable plate, and a lid body covering an opening of the carton body, or a lid part, and a polyolefin resin film on both sides. A carton made by adhering a sheet with a saw blade made of vulcanized fiber on which a moisture-proof film is formed. 5. A carton formed by adhering a sheet with a saw blade made of vulcanized fiber according to claim 4, wherein an emulsion of polyethylene is applied and dried in advance on an adhering portion of the saw blade sheet of the carton blank.